Board Thread:General Discussion/@comment-26222858-20150917141812/@comment-26222858-20150925155109

Anyways, the whole point of this is the Yamato is not Nero's, and as soon as Nero got it, he received a DT. Coincidence? I'd say not, as if his signature sword was a Devil Arm, he would have gotten DT much sooner, but instead he got it from the Yamato. And how do you think Dante achieved a DT? By a Devil Arm, a.k.a. the Rebellion.

tl;dr  The Devil Arms have their own DTs, and Nero happened to achieve Yamato's.